Help! 1986 runs COLD

[Marv02]

I am out here in CA normaly it not very cold out here.

But after the New rebuild I have notice that it run cold.

The outside temps are around 27 in the mornings and 50 in the afternoons.

My water temps are 160 to 170 the oil temp read LOW or 160 or so. at stop lights the oil temps will read low.

Before the rebuild it ran 190 ish range the fans would kick on at 230.

After the rebuild and running the motor in the garage the fans woud kick on around 230 also the water temps were normal the oil temps were lowwer due to the new engine oil cooler that I installed during the rebuild.

Anyone out there know what would cause this.

I also have notice the car starts to miss at a stop light when the oil temps starts reading low temp good oil pressure still around 20 Psi after the car get up to running temps 40 to 50 when cold.

I checked the fans they are NOT always running.

 

[WhalePirot]

What thermostat does it have? Stock water pump? Radiator?

 

[Hib Halverson]

I wanna make sure I understand the symptoms...

Did you say, when idling at a stop light the oil temperature goes down and when you bring the rpm up while driving, it goes up? That is, oil temp swings a number of degrees in the few seconds it takes for the engine to idle down when coming to a stop or accelerating when leaving a stop?

Have you checked coolant temperature with a known good device, such as a mechanical temp gauge or an IR "temp gun"?

 

[Marv02]

Change out the intake manifold gaskets do to the oil leak cahn ge out the Therostat out for the running cold Issues.

I have not driven the car yet I just waiting for the ground to dry out some before I take for a drive.

The road leading up to our garage is a dirt road it mudddy now.

Bt Idleing in the garage the water temp got up to 195 to 200 so thats better.

The good new is when I took the distrbitor cap I found out my NEW rotor was comming apart good find if did come apart driving it that could been a bad thing.

 

[Marv02]

What thermostat does it have? Stock water pump? Radiator?

195 Thermostst, Stock Radiator, Hi Flow Water pump.

Also have aftermarket Engine oil cooler.

 

[Marv02]

I think why my engine oil so cool is the engine oil cooler I have in the oil system.

As for temp swing for the water temp it was 165 Ish during driving but at a light it drop to 155 ish and the oil will show 155 ish at cruise and drop below 150 thats why the temp gauge shows low temp.

I have notice alread with the new Thermostat it got over 200 it would not do that for a whlie.

I wanna make sure I understand the symptoms...

Did you say, when idling at a stop light the oil temperature goes down and when you bring the rpm up while driving, it goes up? That is, oil temp swings a number of degrees in the few seconds it takes for the engine to idle down when coming to a stop or accelerating when leaving a stop?

Have you checked coolant temperature with a known good device, such as a mechanical temp gauge or an IR "temp gun"?

 

[Marv02]

So far it good I took the car for a short drive today the Water temp came to 205.
The oil temp was comming up to normal before I parked it.
And NO more oil leaks

 

[Marv02]

LOL
Just my luck BAD.
The New water pump thatt has 500 Miles on it went bad Figuers it leaking out of the weep hole.

 

[WhalePirot]

The New water pump that has 500 Miles on it went bad Figures it leaking out of the weep hole.

Are you sure you need a high flow pump? In talking with cooling experts at BeCool, I learned that the coolant can move too fast to do a good job at pulling heat from the motor, and not leaving it in the radiator long enough to lose that heat. Actually, few car guys know that or that the thermostat is not a static device, but opens and closes constantly, to regulate towards the design temperature.

 

[boomdriver]

Thats all pretty normal for a system thats got a thermostat thats stuck open or too low. Mine ran exactly 163 degrees in the winter/spring when I lived in SoCal and had a 160 stat installed with a bypass hole. The oil temps creep up as rpm does, slowly drop as engine load does. The oil cools the motor as much as the water does.

The key to good tuning is a stable operating temp. 160 is too cold. The oil needs to be hotter to evaporate moisture out and prevent sludge and acids from forming. The ECM needs to see hotter temps to get that optimal fuel/air ratio and acheive a good, clean burn for the o2 sensor to see.
The misfire you see at idle is most likely from a fouled plug or trying to foul since the motor is running a bit rich at those temps.
The hi-flow water pump is a great idea and I have used one for many years. IF there was an issue with excessive water flow, having too much flow is very easy to manage by installing an orifice in the system to slow the flow so water takes longer to exit the heads. The stock system comes with an orifice to maintain back pressure in the heads and intake to help eliminate hot-spots due to water escaping to quickly. There is nothing that can be done about having too little flow...too much gives you something to work with.
Flow from the stock pump is minimal at idle, and cooling efficiency is marginal at idle/low rpm in traffic with low or no fresh air flowing into the nose. What air it gets is ground surface heated air, often thick with ground level ozone during summer months. Not great for cooling efficiency.
The hi flow pump moves more water, collecting more heat as it travels and allowing for more exchange in the radiator (heat exchanger).As long as there IS a temp differential there will be heat exchange. The greater the differential, the more the exchange. So, efficiency in the radiator creates that differential so there is cooler water entering the engine.

There are 2 things that have to happen in heat exchange, the movement of a heat conductor (water) and the movement of air thru the exchanger. Anytime one or the other increases, so does efficiency. Because the normal fan temps come on at 230 degrees, the majority of exchange comes from the car moving thru the air where it scoops air thru the nose into the exchanger. Same for the hot a/c condensor that can sometimes be hotter than the radiator, so that needs to be considered as well. Blowing super heated air into a heat exchanger does not help keep the temp differential as wide as you'd like. Sucking in 80* air to cool 220* water gives a nice wide differential. The a/c condensor can ruin that if the a/c system is not in good shape or partially clogged causing the condensor to run too hot. That excess heat goes directly to the radiator,. What should happen is the condensor should run at a temp that helps to maintain a stable temp in the nose so the minimal temp differential is maintained.

Bottom line, your car sounds normal. Temps need to be brought up so they are stable at around 190-200, maybe a bit less at cruising speed. A slight increase in traffic is expected.
Having a "enhanced" motor generates more heat, faster than a stock so the cooling system should be equally as enhanced. The hi-flow pump is one piece but the single best thing that can be purchased for ANY C4 is a good all aluminum 2 row HD radiator. It is very efficient, allows for good quick heat exchange, holds more coolant and looks pretty darn good too!
Heres the link where I got mine...came with new sensor, cap and fittings for under $250. a GREAT DEAL.
Engineered Cooling Products items - Get great deals on items on eBay Stores!

My temps in the hot sticky Gulf Coast climates were hitting 240+ in traffic, now they run 200-210 (with a/c on) in stop-n-go traffic....best money ever spent on my car. Put a 190 thermostat in and I can assure you that the temp will remain right around 190+/- 5 degrees idling or cruising.
Once the water temp is stable the oil temp will fall in line and should be close to water temp but slower to go up or down.

I am out here in CA normaly it not very cold out here.

But after the New rebuild I have notice that it run cold.

The outside temps are around 27 in the mornings and 50 in the afternoons.

My water temps are 160 to 170 the oil temp read LOW or 160 or so. at stop lights the oil temps will read low.

Before the rebuild it ran 190 ish range the fans would kick on at 230.

After the rebuild and running the motor in the garage the fans woud kick on around 230 also the water temps were normal the oil temps were lowwer due to the new engine oil cooler that I installed during the rebuild.

Anyone out there know what would cause this.

I also have notice the car starts to miss at a stop light when the oil temps starts reading low temp good oil pressure still around 20 Psi after the car get up to running temps 40 to 50 when cold.

I checked the fans they are NOT always running.